package com.roll.casserole.nio.channel;

import java.nio.MappedByteBuffer;
import java.io.OutputStream;
import java.io.InputStream;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;
import java.util.EnumSet;

import static java.nio.file.LinkOption.NOFOLLOW_LINKS;

/**
 * <p>@author roll
 * <p>created on 2020/9/4 12:14 下午
 */
public class Main {
    public static void deleteCopied(Path path) {

        try {
            Files.deleteIfExists(path);
        } catch (IOException ex) {
            System.err.println(ex);
        }

    }

    public static void main(String[] args) {

        final Path copy_from = Paths.get("C:/rafaelnadal/tournaments/2009/videos/ Rafa Best Shots.mp4");
        final Path copy_to = Paths.get("C:/Rafa Best Shots.mp4");
        long startTime, elapsedTime;
        int bufferSizeKB = 4; //also tested for 16, 32, 64, 128, 256 and 1024
        int bufferSize = bufferSizeKB * 1024;
        deleteCopied(copy_to);
        //FileChannel and non-direct buffer
        System.out.println("Using FileChannel and non-direct buffer ...");
        try (FileChannel fileChannel_from = (FileChannel.open(copy_from, EnumSet.of(StandardOpenOption.READ)));
             FileChannel fileChannel_to = (FileChannel.open(copy_to, EnumSet.of(StandardOpenOption.CREATE_NEW, StandardOpenOption.WRITE)))) {
            startTime = System.nanoTime();
            // Allocate a non-direct ByteBuffer
            ByteBuffer bytebuffer = ByteBuffer.allocate(bufferSize);

            // Read data from file into ByteBuffer
            while (fileChannel_from.read(bytebuffer) > 0) {
                //flip the buffer which set the limit to current position, and position to 0
                bytebuffer.flip();
                //write data from ByteBuffer to file
                fileChannel_to.write(bytebuffer);
                //for the next read
                bytebuffer.clear();
            }

            elapsedTime = System.nanoTime() - startTime;
            System.out.println("Elapsed Time is " + (elapsedTime / 1000000000.0) + " seconds");
        } catch (IOException ex) {
            System.err.println(ex);
        }

        deleteCopied(copy_to);

        //FileChannel and direct buffer
        System.out.println("Using FileChannel and direct buffer ...");
        try (FileChannel fileChannel_from = (FileChannel.open(copy_from, EnumSet.of(StandardOpenOption.READ)));
             FileChannel fileChannel_to = (FileChannel.open(copy_to, EnumSet.of(StandardOpenOption.CREATE_NEW, StandardOpenOption.WRITE)))) {
            startTime = System.nanoTime();
            // Allocate a direct ByteBuffer
            ByteBuffer bytebuffer = ByteBuffer.allocateDirect(bufferSize);
            // Read data from file into ByteBuffer
            while (fileChannel_from.read(bytebuffer) > 0) {
                // flip the buffer which set the limit to current position, and position to 0
                bytebuffer.flip();
                // write data from ByteBuffer to file
                fileChannel_to.write(bytebuffer);
                // for the next read
                bytebuffer.clear();
            }

            elapsedTime = System.nanoTime() - startTime;
            System.out.println("Elapsed Time is " + (elapsedTime / 1000000000.0) + " seconds");
        } catch (IOException ex) {
            System.err.println(ex);
        }

        deleteCopied(copy_to);

        //FileChannel.transferTo()
        System.out.println("Using FileChannel.transferTo method ...");
        try (FileChannel fileChannel_from = (FileChannel.open(copy_from, EnumSet.of(StandardOpenOption.READ)));
             FileChannel fileChannel_to = (FileChannel.open(copy_to, EnumSet.of(StandardOpenOption.CREATE_NEW, StandardOpenOption.WRITE)))) {

            startTime = System.nanoTime();

            fileChannel_from.transferTo(0L, fileChannel_from.size(), fileChannel_to);

            elapsedTime = System.nanoTime() - startTime;
            System.out.println("Elapsed Time is " + (elapsedTime / 1000000000.0) + " seconds");
        } catch (IOException ex) {
            System.err.println(ex);
        }

        deleteCopied(copy_to);

        //FileChannel.transferFrom()
        System.out.println("Using FileChannel.transferFrom method ...");
        try (FileChannel fileChannel_from = (FileChannel.open(copy_from,
                EnumSet.of(StandardOpenOption.READ)));
             FileChannel fileChannel_to = (FileChannel.open(copy_to, EnumSet.of(StandardOpenOption.CREATE_NEW, StandardOpenOption.WRITE)))) {

            startTime = System.nanoTime();

            fileChannel_to.transferFrom(fileChannel_from, 0L, (int) fileChannel_from.size());

            elapsedTime = System.nanoTime() - startTime;
            System.out.println("Elapsed Time is " + (elapsedTime / 1000000000.0) + " seconds");
        } catch (IOException ex) {
            System.err.println(ex);
        }

        deleteCopied(copy_to);

        //FileChannel.map
        System.out.println("Using FileChannel.map method ...");
        try (
                FileChannel fileChannel_from = (FileChannel.open(copy_from,
                        EnumSet.of(StandardOpenOption.READ)));
                FileChannel fileChannel_to = (FileChannel.open(copy_to, EnumSet.of(StandardOpenOption.CREATE_NEW, StandardOpenOption.WRITE)))) {

            startTime = System.nanoTime();
            MappedByteBuffer buffer = fileChannel_from.map(FileChannel.MapMode.READ_ONLY, 0, fileChannel_from.size());

            fileChannel_to.write(buffer);
            buffer.clear();

            elapsedTime = System.nanoTime() - startTime;
            System.out.println("Elapsed Time is " + (elapsedTime / 1000000000.0) + " seconds");
        } catch (IOException ex) {
            System.err.println(ex);
        }
        deleteCopied(copy_to);
        //Buffered Stream I/O
        System.out.println("Using buffered streams and byte array ...");
        File inFileStr = copy_from.toFile();
        File outFileStr = copy_to.toFile();
        try (BufferedInputStream in = new BufferedInputStream(new FileInputStream(inFileStr));
             BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream(outFileStr))) {
            startTime = System.nanoTime();
            byte[] byteArray = new byte[bufferSize];
            int bytesCount;
            while ((bytesCount = in.read(byteArray)) != -1) {
                out.write(byteArray, 0, bytesCount);
            }
            elapsedTime = System.nanoTime() - startTime;
            System.out.println("Elapsed Time is " + (elapsedTime / 1000000000.0) + " seconds");
        } catch (IOException ex) {
            System.err.println(ex);
        }
        deleteCopied(copy_to);
        System.out.println("Using un-buffered streams and byte array ...");
        try (
                FileInputStream in = new FileInputStream(inFileStr);
                FileOutputStream out = new FileOutputStream(outFileStr)) {
            startTime = System.nanoTime();
            byte[] byteArray = new byte[bufferSize];
            int bytesCount;
            while ((bytesCount = in.read(byteArray)) != -1) {
                out.write(byteArray, 0, bytesCount);
            }
            elapsedTime = System.nanoTime() - startTime;
            System.out.println("Elapsed Time is " + (elapsedTime / 1000000000.0) + " seconds");
        } catch (IOException ex) {
            System.err.println(ex);
        }

        deleteCopied(copy_to);
        System.out.println("Using Files.copy (Path to Path) method ...");
        try {
            startTime = System.nanoTime();
            Files.copy(copy_from, copy_to, NOFOLLOW_LINKS);
            elapsedTime = System.nanoTime() - startTime;
            System.out.println("Elapsed Time is " + (elapsedTime / 1000000000.0) + " seconds");
        } catch (IOException e) {
            System.err.println(e);
        }

        deleteCopied(copy_to);
        System.out.println("Using Files.copy (InputStream to Path) ...");
        try (InputStream is = new FileInputStream(copy_from.toFile())) {
            startTime = System.nanoTime();
            Files.copy(is, copy_to);
            elapsedTime = System.nanoTime() - startTime;
            System.out.println("Elapsed Time is " + (elapsedTime / 1000000000.0) + " seconds");
        } catch (IOException e) {
            System.err.println(e);
        }

        deleteCopied(copy_to);
        System.out.println("Using Files.copy (Path to OutputStream) ...");
        try (OutputStream os = new FileOutputStream(copy_to.toFile())) {
            startTime = System.nanoTime();
            Files.copy(copy_from, os);
            elapsedTime = System.nanoTime() - startTime;
            System.out.println("Elapsed Time is " + (elapsedTime / 1000000000.0) + " seconds");
        } catch (IOException e) {
            System.err.println(e);
        }
    }
}
